Expression profiling of anoxia-responsive genes and changes in both antioxidative enzymes and lipid peroxidation in rice seedlings under anoxia stress

The effect of complete submergence on growth attributes of rice via morphological screening. Four (W0, W2, W6 and W10) of twenty-seven varieties were screened and further used to test for changes in antioxidative enzymes, lipid peroxidation and the expression of anoxia-responsive genes in plants under complete submergence. Antioxidative enzymes such as SOD, CAT and POD increased significantly in W6 and W10; however, POD and CAT decreased greatly, and SOD showed no change in W0 or W2 on 6th and 8th days of submergence. In addition, malondialdehyde (MDA) content was significantly more enhanced in W0 and W2 than in W6 and W10. The expression level of ADH1, CIPK15, SnRK1A, SUB1A, SLRL1 and SUB1C increased significantly in W10 but decreased in W2, except for SUB1A and SLRL1 on the 4th day of submergence. The results of the current study suggest that rice varieties with better shoot and root growth sustained high survival rates. Antioxidative enzymes activities must be higher in resistant varieties. Our results further suggest that submergence induces the expression of SUB1A, which further promotes the expression of SLRL1, a central suppressor of GA signaling, and improves tolerance to submergence stress in tolerant varieties by inducing expression of enzymes responsible for the detoxification of ROS.